fix: seed initial state from last 8KB of log on startup

log_watcher.py

@@ -7,6 +7,7 @@ from typing import Callable, Awaitable, Optional
 class LogWatcher:
     POLL_INTERVAL = 0.1
     FILE_RETRY_INTERVAL = 1.0
+    SEED_BYTES = 8192  # read last ~8 KB on open to seed initial state
 
     def __init__(
         self,
@@ -35,7 +36,11 @@ class LogWatcher:
         while True:
             try:
                 with open(self._path, 'r', errors='replace') as f:
-                    f.seek(0, 2)  # start at end of file (tail -f behaviour)
+                    f.seek(0, 2)
+                    end = f.tell()
+                    f.seek(max(0, end - self.SEED_BYTES))
+                    if f.tell() > 0:
+                        f.readline()  # discard partial first line
                     offline_since = None
                     while True:
                         line = f.readline()